Now, a wearable sleeping bag is not a Snuggie, a Slanket, or any number of similarly named, as-seen-on-TV, indoor-use, fleece-y blankets-with-arms. It is also not a snowsuit, a ski suit, or a rain suit. A wearable sleeping bag is built like a sleeping bag, which is to say that it is insulated and often comes with a temperature rating. Like a normal sleeping bag, if a wearable one gets soaked, it becomes a soggy mess and will lose much of its heat-sealing power. And if you snag it on a sharp edge, it will rip open, and a blizzard of fluffy white stuff will float down on you like you’re off-piste in Aspen.